The present invention relates to a signal transmitter.
It is a well-known fact that seriously handicapped people, or indisposed or older persons not being continuously supervised, for whom sudden accidents and illness could be a disaster, are not able, if such an occasion should occur, to call upon the attention of people nearby or inform them about the existing situation by using the telephone, alarm devices or the like and hence, they may lie helpless without receiving appropriate care for a long period of time. This situation can result in the death of such persons.
In order to solve this problem it has among other things been suggested that an additional switch, be provided in connection with e.g. the wall switch for the electric light, whereby upon the manual actuation of such a wall switch the additional switch is also actuated, thereby transmitting a signal to an alarm bell timer or the like, which then is re-set to zero. When such additional switches are provided in connection with all the existing wall switches of a dwelling, a clinic, a home for the aged, or the like and also in connection with the switches for the electrical hearth-plates, television sets etc., actuation of such an additional switch will re-set the alarm bell timer to zero.
In case no such switch is actuated during a predetermined period of time, i.e. if the alarm bell timer is not re-set to zero, the bell, which e.g. can be located at the next-door neighbor, at a porter, or at the outer door of the room of the person in question, alarms indicating that an unanticipated serious accident has occurred.
The use of the system with additional switches in connection with the existing switches has a plurality of drawbacks. The additional switches must be provided in the immediate vicinity of or be connected to the existing switches in order to have the desired effect, which often necessitates an expensive installation and/or redesign. Additionally, in case a low voltage D.C. or A.C. current is supplied to the alarm system, which of course is preferable from the security and cable dimensioning point of view, switches operating with low voltage A.C. or D.C. current are not permitted to be coupled together, according to the Boards for Testing and Approval of Electrical Equipment, with switches connected to the electrical mains, which is a fact preventing such devices from being used.